Summary Eesti Loodus 2012/10

 Summary

How to recognize an insect. II Palaeoptera

Mati Martin continues introducing the diversity of insects. This time he focuses on Ephemoroptera (mayflies) and dragonflies, from the division Palaeoptera. The name Palaeoptera has been traditionally applied to those ancestral groups of winged insects that lacked the ability to fold the wings back over the abdomen as characterizes the Neoptera. Both orders are described in order to point out special characteristics. Dragonflies as larger and more distinctive are easier to recognize, especially hawkers, the biggest among dragonflies. The colourful photographs demonstrate the specifics of these beautiful and somewhat mystic insects.

 

Fishing sport clubs as managers of Estonian inland waters

Kalle Kroon describes the activities of fishers before and after the World War II, stressing their importance in protecting and enhancing the fish resources. The first fishing societies in Estonia were founded in 1930ies, and re-established and reorganized in the Soviet times. The author brings good examples of the activities of such societies, and their positive effect on fish resources. Unfortunately, in nowadays Estonia no fishing societies are responsible for managing any waterbodies.

 

Forest provided food, medicine and coating

Lembitu Tverdjanski (Tarand), Triin Kusmin and Jürgen Kusmin look back at how forest goods were used in households. They describe slash-and-burn agriculture, forest apiculture, making brushwood, and shoes made of bass. All these activities have almost disappeared for now, with one exception: picking forest goods and medical herbs from the forest. In old times, tree sap had a large role in people’s diet.

 

Bird of the year: Diehard

Mall Hiiemäe summarizes the folk knowledge about partridge. The author has looked into literature and archives to find out how people have described the sounds that partridges make, and how they have interpreted the different activities and behavior of the bird. Also, different ways to hunt the partridge are described.

 

Tree of the year: An old guelder rose fights with bugs

Villu Anvelt noticed caterpillars eating on the leaves of an old and large guelder rose, and Mati Martin explains that these were the offspring of viburnum leaf beetles.

 

Interview: Tartu Nature House is facing better future

Toomas Kukk has interviewed Janika Ruusmaa, the head of the Tartu Environmental Education Centre.

 

Estonian Nature enquires

Märt Rahi explains the role of virtual photo gallery of Estonian lakes.

Tiit Teder writes why some berries are poisonous for mammals, but not for birds, who play an important role in spreading the seeds.

 

Hawk owls nested on the Räpina polder

Toomas Mastik and Kadri Niinsalu observed hawk owls and their offspring through the lenses of their cameras. The last time hawk owls were seen nesting in Estonia was 38 years ago. This spring the hawk owl couple raised three chicks. The family was very brave and not at all afraid of humans. Their diet consisted of mice and rats.

 

The giant trees of North America

Hendrik Relve shares impressions from his trip to Olympic National Park (US). As a result, many tree giants were remeasured and their perimeters specified. The narrow strip of North-American rainforest extends from Alaska to San Fransisco and is a home for especially large trees. As the relief is very complicated, involving high mountains and thick forests, it is rather difficult to measure the trees. However, the team succeeded in conquering and measuring several tree giants, including the biggest Sitka spruce and Western redcedars. Most tree giants have intriguing trunk shapes, which are well depicted on the supplemented photographs.

 

Changes in salicology

Mati Laane’s article about new postures in the systematics and diversity of willows gives some idea of the hardships the plant systematics scientists as well as gardeners have to face. The willow species are in constant change, mutating and providing hybrids and variations. Though exciting for scientists to observe, such changes bring about hardships in systematics and endless disputes. The author concentrates on the changing systematics of great willows, bringing detailed examples of different opinions.

 

The ozone layer will be continuously protected

Kaidi Virronen gives an overview of the Montreal Treaty and the current status of the ozone layer, in order to mark International Day for the Preservation of the Ozone Layer (September 16th). The Montreal treaty, signed in 1987, and ratified by 197 countries, has fortunately helped to improve the condition of the ozone layer quite a lot. The scientists believe that the ozone layer will recover by the end of this century, assuming that the Montreal treaty is followed.